1. Field of Invention
The present invention relates to a light emitting device and a manufacturing method thereof. More particularly, the present invention relates to an organic light emitting device and a manufacturing method thereof.
2. Description of Related Art
An organic light emitting device offers a variety of desirable features, such as a thin-body implementation, self-emissive property, low power consumption, no backlight source, a wide viewing angle, and a high reaction rate, etc. Thus, in recent years, an organic light emitting device has become the mainstream of flat screen displays. Moreover, a passive organic light emitting device may be formed as an array structure on a light and thin, flexible substrate. Hence, an organic light emitting device is also suitable for illumination purposes. Typically, the light emitting efficiency of an organic light emitting device is estimated to increase to 100 Lm/W or higher, and the color rendering index is higher than 80. Accordingly, an organic light emitting device has a potential to replace a typical illumination light source and to serve an important role in illumination apparatuses.
In an organic light emitting device that has a large area, since such a device is driven by current, the trace impedence may induce non-uniform brightness in the light emitting region. Hence, an organic light emitting device having a large area is normally divided into a plurality of small-area light emitting units. Moreover, the laterally extended light emitting units are serially connected, while the serially connected light emitting units are also connected in parallel. In other words, a bridge circuit is disposed between two neighboring light emitting units to provide uniform brightness in the light emitting region. However, the disposition of the above bridge circuit will lower the overall aperture ratio of the organic light emitting device.